/usr/share/doc/libgtkimageview-doc/html is in libgtkimageview-dev 1.6.4+dfsg-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgtkimageview-doc/../../gtk-doc/html/gtkimageview
/usr/share/doc/libgtkimageview-doc/../../gtk-doc/html/gtkimageview